Key Delivery

Abstract

A multi-hierarchical key system is provided such that users receive timely key renewals when required so that access to authorized content is not disrupted. Timely renewals of keys may occur continuously for various services while minimizing network traffic. The multi-hierarchical key system may be used in an adaptive streaming environment.

We claim: 
     
         1 . A device comprising:
 a memory storage area storing a license having a signature, the license including at least one key;   a processor in communication with the memory storage and configured to perform the following:   decrypting the license using a device key;   verifying the signature in the decrypted license;   storing the at least one key in the memory storage area;   receiving a content stream; and   decrypting the received content stream using the at least one key stored in the memory storage area.   
     
     
         2 . The device of  claim 1 , wherein the at least one key comprises a group of keys, the group of keys forming a hierarchy of keys. 
     
     
         3 . The device of  claim 2 , wherein the group of keys includes at least two service keys. 
     
     
         4 . The device of  claim 3 , wherein a last service key, of the at least two service keys, encrypts a content key. 
     
     
         5 . The device of  claim 4 , wherein the first service key is encrypted by the device key. 
     
     
         6 . The device of  claim 2 , wherein the group of keys includes at least one service key and at least one content key. 
     
     
         7 . The device of  claim 1 , further comprising receiving an updated license, the updated license including at least one new key. 
     
     
         8 . The device of  claim 7 , wherein the at least one new key comprises a group of new keys, the group of new keys forming a revised hierarchy of keys. 
     
     
         9 . The device of  claim 1 , wherein the device key is unique to the device. 
     
     
         10 . The device of  claim 1 , wherein the processor comprises a trusted processor of a system on a chip. 
     
     
         11 . The device of  claim 1 , wherein the processor comprises a secure microprocessor. 
     
     
         12 . The device of  claim 1 , wherein the received content stream comprises a fragmented content stream. 
     
     
         13 . A method, comprising:
 receiving a license in a streaming environment, the license including at least one service key;   decrypting, by a processor, the license using a device key;   using the at least one service key to decrypt a service package, by the processor, the service package including at least one content key;   receiving a content stream; and   decrypting, by the processor, the received content stream using the at least one content key.   
     
     
         14 . The method of  claim 13 , wherein the content stream comprises a fragmented content stream. 
     
     
         15 . The method of  claim 13 , wherein the streaming environment comprises an adaptive streaming environment. 
     
     
         16 . The method of  claim 13 , further comprising:
 receiving a renewed service key;   decrypting, by the processor, a second service package using the renewed service key, the second service package including new content keys; and   decrypting, by the processor, a received content stream using the new content keys.   
     
     
         17 . The method of  claim 16 , wherein the renewed service key is received based on a predetermined schedule. 
     
     
         18 . A method, comprising:
 determining multicast groups based on service offerings;   encrypting a license using a device key, the license including a hierarchy of keys, wherein the hierarchy of keys includes at least a service key and a content key;   transmitting the license in a content stream; and   transmitting a renewed service key based on the determined multicast groups.   
     
     
         19 . The method of  claim 18 , wherein the renewed service key is transmitted based on a predetermined schedule. 
     
     
         20 . The method of  claim 18  wherein the predetermined schedule is based on a multicast group.